1. Field of the Invention
This invention relates to the preparation isocyanate-containing acrylic polymers and more particularly to polydisperse low-molecular weight polymers having terminal monosulfide groups and low toxicity.
2. Prior Art
Bortnick U.S. Pat. No. 2,718,516 (1955) describes high-molecular weight polymers based on (meth)acrylic ester isocyanates and containing a plurality of isocyanate groups (see Comparative Example A, below).
Certain organic polyisocyanates of low molecular weight are used commercially, e.g., as crosslinking agents. In some cases, these have recently been found to contain, upon aging, excessive levels of residual monomeric diisocyanate, thereby increasing the toxicity.